I beg your pardon ?
First they say "AdSense for domains allows domain name registrars ... to provide valuable and relevant content on their parked pages,"
Then they say "Parked domain pages generally have no content.."
Sorry, but logic commands those two sentences to be mutually exclusive.
That's like me telling you I only dress in red while wearing white sneakers, black pants and a white shirt.
Will you believe me if I smile ?